Most of Monday’s problems came in the Northeast, where long delays popped up at airports in New York, Philadelphia, Washington and Baltimore as thunderstorms and torrential rains moved across the region.

Conditions eased around Washington and Baltimore as the storms moved east by late morning, but the New York, Philadelphia and Boston airports saw major disruptions into the evening.

The problems in the Northeast follow another round of major flight disruptions that snarled airports in the Midwest during the weekend. About 2,000 combined flights were canceled Saturday and Sunday as a late-season blizzard forced airports like Minneapolis/St. Paul and Sioux Falls, S.D., to suspend flights for extended periods of the weekend.

Conditions in the Midwest had improved by Monday, but fliers should expect some residual flight irregularities as airlines get their planes and crews back into place there.

A Cathay Pacific flight readies for take off from Hong Kong on Nov. 8, 2017.
Qatar Airways has bought a stake in Cathay Pacific, it announced on November 6, giving the Doha-based airline a toehold in the potentially lucrative Asian aviation market. / AFP PHOTO / ANTHONY WALLACEANTHONY WALLACE/AFP/Getty Images ORIG FILE ID: AFP_U32B6

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A make-up artist applies make-up to a United Airlines flight attendant dressed in a retro 1970s-themed uniform before taking part in the final Boeing 747 flight for the airline on Nov. 7, 2017.

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Mechanic Ron Lostica poses for a photo onboard United Airlines' last Boeing 747 jet before it made its final passenger flight on Nov. 7, 2017. Mr. Lostica, a 31-year United veteran, wore a Boeing 747 hat from a delivery in the 1990s.

A passenger aboard United Airlines last Boeing 747 flight poses for a portrait on Nov. 7, 2017.

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A flight of Australian low-cost carrier JetStar taxis at Sydney's Kingsford Smith International Airpor on Nov. 27, 2017.

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An Airbus A320 aircraft with the logo and colours of Joon - the new lower-cost airline subsidiary of Air France - moves at the Charles de Gaulle Airport on Nov. 30, 2017. The airline debuted service on Dec. 1.

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A United Airlines Boeing 737 departs over an arriving Spirit Airlines Airbus A319 at Boston Logan International Airport on November 25, 2017.

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Crews work to de-ice jets during an unexpectedly strong snow storm at Atlanta-Hartsfield International Airport on Dec. 8, 2017.

A Delta Air Lines Boeing 757-200 taxis out to depart from Atlanta-Hartsfield International Airport on Dec. 8, 2017.

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An Airbus A320 painted in the colors Joon, the new airline subsidiary of Air France are soon on the apron at the Paris Charles de Gaulle Airport on Nov. 30, 2017. The airline debuted service on Dec. 1.

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A Delta Air Lines Boeing 757-200 departs Seattle-Tacoma International Airport in December 2017.

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A Southwest Airlines Boeing 737 MAX 8 jet lands at Seattle-Tacoma International Airport in December 2017.

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Cardinals wave goodbye to a Bangladesh Airlines aircraft In Dhaka carrying Pope Francis after his three-day visit to Bangladesh on Dec. 2, 2017.